Measurements of the residual resistivity, and positron annihilation spectroscopy, were used to study the formation and annealing of radiation defects in Fe-36.5%Ni and Fe-36.5Ni-0.1%P alloys which had been irradiated with 5.5MeV electrons at 270K. It was shown that, during irradiation, vacancy migration and the formation of vacancy clusters could occur. The vacancy clusters in the Fe-Ni-P alloy were finer, than those in the Fe-Ni alloy, because of the interaction of vacancies with P atoms. During annealing (500K), the vacancy clusters broke up and partly transformed into vacancy loops that were stable at up to 700K. The migration of vacancies and self-interstitials during irradiation, and the break-up of vacancy clusters during subsequent annealing, stimulated the formation of local short-range order.

Accumulation and Annealing of Radiation Defects in Fe-Ni and Fe-Ni-P Electron-Irradiated Alloys. V.L.Arbuzov, S.E.Danilov, A.P.Druzhkov, V.A.Pavlov: Physics of Metals and Metallography, 2000, 89[4], 373-7